The subject invention relates to lightweight nonwoven polymeric fiber mat composites and preferably, lightweight nonwoven polymeric fiber mat composites that are only coated on one major surface and are particularly well suited for use: as an underlayment in various building construction applications, such as but not limited to roofing underlayment applications, housewrap applications, non-slip surface applications, etc. and as facers for fibrous insulation boards, foam insulation boards, fibrous sheathing boards, foam sheathing boards, etc.
In a typical residential roofing construction, a roofing underlayment is installed on the wooden roof deck prior to installing the asphalt shingle, shake shingle, tile, or metal roofing system on the deck. The most common underlayments currently used in residential roofing construction are asphalt saturated organic felt underlayments that conform to ASTM Standard D 4869-02 entitled “Standard for Asphalt-Saturated Organic Felt Underlayment Used in Steep Slope Roofing”, or ASTM D226. The asphalt saturated organic felt underlayments typically used with standard performance roofing shingle products are the No. 15 underlayments and the asphalt saturated organic felt underlayments typically used with higher performance roofing shingle products are the heavier No. 30 underlayments.
A primary purpose of the roofing underlayment is to provide a water transmission resistant or water shedding layer over the wooden roof deck prior to the installation of the residential roofing system on the deck. It is common roofing practice to build up redundant or multiple water shedding layers over the roof deck. With building construction schedules, including unanticipated delays in these schedules, the water transmission resistant layer to be formed by these roofing underlayments can be in place on the wooden roof deck for many months prior to the installation of the roofing system and is thus intended to protect the wooden roof deck from water damage due to inclement weather during this period. Once a roofing system is installed, a secondary purpose of these roofing underlayments is to provide another layer of water transmission resistant protection below the shingles, should water enter the roofing system due to wind driven rain, snow or ice buildup, or damaged or missing shingles.
With longer service life shingles coming into greater use, there has been and continues to be a need for roofing underlayments that have a longer service life and improved physical properties such as: a higher tear strength so that the underlayments can not be as easily torn during installation or while exposed on a roof deck during subsequent construction activity; a higher resistance to deterioration when left exposed to the weather for more than a few days; a greater resistance to fastener pull through so that the underlayments are not blown away or torn during exposure to inclement weather conditions; a greater resistance to deterioration when installed under a shingle layer in a roofing system; and a greater resistance to fungi growth while in service.